Audio file artwork rules

[simbun]

I was looking at these rules to see if using the embedded artwork during playback could ever be the wrong thing to do. The current MinimServer documentation describes a scenario where that could give incorrect results, but the current implementation differs from that.

Within MinimServer, the only reason it may be beneficial for an external image (filename.jpg) to override an embedded one is because the embedded image forms part of the album artwork ruleset (which trackname.jpg does not), so the only way to implement a track override would be at the filename level.

I only have a few instances where I've needed to use embedded artwork (and that's only because I'm using a pseudo album tag to help with attribution), so I'm more than happy with simply modifying the documentation.